How We Solved a Loose Bar-End Mirror on a 2019 Triumph Street Scrambler
At a glance: This article is based on an anonymized KiWAV customer-support case from 2021. The motorcycle was a 2019 Triumph Street Scrambler with its original handlebar. The rider reported that the bar-end mirror mount was still loose after tightening the mounting bolt. After reviewing the rider's photos and video, KiWAV identified the supplied bolt length as the problem and sent shorter M6 × 20 mm bolts. On 5 July 2021, the rider confirmed that the shorter bolts had solved the installation.
Cover image: KiWAV Eclipse bar-end mirrors installed on a Triumph. Representative KiWAV product photo; this is not the customer's 2019 Street Scrambler from the 2021 support case.
Case timeline
| Date | What happened |
|---|---|
| 8 June 2021 | The rider described a 2019 Triumph Street Scrambler with its original handlebar and asked about mirror fitment. |
| 21 June 2021 | After receiving the mirrors, the rider reported that the bar-end mount was loose and sent photos and video for review. |
| 22 June 2021 | KiWAV product support reviewed the installation and identified that the standard-length bolts were too long for this particular mounting setup. |
| 24 June 2021 | KiWAV sent shorter M6 × 20 mm bolts and a video explaining how to adjust the firm mirror joint safely. |
| 5 July 2021 | The rider confirmed that the shorter bolts worked and the installation issue was resolved. |
The problem: the bolt felt tight, but the mirror mount was still loose
On 21 June 2021, the rider reported that the Eclipse bar-end mirror mount remained loose after installation. The motorcycle was described as having its original handlebar.
This type of problem cannot be diagnosed by handlebar diameter alone. Two separate parts of the installation must be considered:
- Does the mirror base sit firmly against the end of the handlebar when the bolt is tightened?
- Is the bolt short enough to tighten the mirror base before reaching the end of the available threaded depth?
A mounting bolt can feel tight even when the mirror base is not properly secured.
If the bolt reaches the end of the threaded hole first, it cannot continue pulling the mirror base against the handlebar. The bolt may appear fully tightened, but the mirror mount can still rotate or feel loose.
What we found in this case
The Eclipse bar-end cap is designed to fit both 7/8-inch and 1-inch handlebars. Because of this design, it may initially feel slightly loose on a 7/8-inch bar before the mounting bolt is tightened. That initial movement does not necessarily indicate a fitment problem.
In this particular Street Scrambler installation, however, KiWAV product support reviewed the rider’s photos and video and concluded that the supplied standard-length bolts were too long for the available mounting depth.
The bolts were reaching the end of the threaded mounting point before the mirror base had been pulled firmly against the handlebar.
On 24 June 2021, KiWAV sent a pair of shorter M6 × 20 mm bolts. The rider later confirmed that the shorter bolts allowed the mirrors to be secured correctly.
How the current hardware addresses this issue
The current KiWAV Eclipse kit for compatible Triumph water-cooled motorcycles includes both:
- M6 × 25 mm bolts × 2
- M6 × 20 mm bolts × 2
The shorter M6 × 20 mm option addresses the bolt-bottoming issue documented in this 2021 installation. A rider encountering the same specific mounting condition should therefore normally no longer need to request shorter replacement bolts separately.
This does not mean that every Street Scrambler requires the M6 × 20 mm bolts. The correct bolt length depends on the motorcycle’s compatible OEM bar-end setup and the available threaded depth.
The important point is that the current package provides both mounting options, allowing the appropriate bolt length to be selected during installation.
How to identify a bolt that is too long
A mounting bolt may be too long if:
- the bolt stops turning but the mirror base is still loose;
- there is still a visible gap between the mirror base and the handlebar end;
- the mirror mount can be rotated even though the bolt feels tight; or
- additional tightening does not pull the mirror base closer to the handlebar.
Do not continue forcing the bolt if it appears to have reached the end of the threaded hole. Excessive tightening may damage the bolt, the internal thread or the handlebar insert.
Instead, compare the supplied bolt lengths and use the option that allows sufficient thread engagement while fully securing the mirror base.
Installation checks before riding
- Confirm the handlebar setup.
This fitment is intended for compatible motorcycles with their original handlebars. Aftermarket handlebars, modified grips, replacement internal weights or previous repairs may change the mounting dimensions. - Make sure the mirror base sits flat.
The mounting surface should sit squarely against the handlebar end without an abnormal gap. - Check that the bolt has not bottomed out.
The mirror base should become secure as the bolt is tightened. A tight bolt with a loose mirror base may indicate that the bolt is too long. - Check the throttle clearance.
On the throttle side, make sure the mirror base does not press against the grip. The throttle must return freely after being released. - Turn the handlebars fully in both directions.
Confirm that the mirrors, controls, cables, brake hose and levers do not contact the fuel tank or other parts of the motorcycle. - Perform a final stability check.
Before riding, apply firm hand pressure to the mirror mount and confirm that it does not rotate around the handlebar end.
The mirror adjustment was a separate issue
The rider also found the mirror angle difficult to adjust.
This was separate from the loose mounting problem. The mounting bolt controls how securely the entire mirror assembly is attached to the handlebar, while the mirror joint controls the viewing angle.
In the support response, KiWAV explained that the Eclipse mirror joint was intentionally firm to help the mirror maintain its position during riding.
The adjustment video demonstrated that the mirror should be adjusted by holding the outer edge of the mirror housing—not by pressing or levering against the mirror glass.
For this installation, mounting the mirrors in the upward position was also suggested to improve the available rear view and clearance.
What this case demonstrates
This documented case shows how a bar-end mirror can remain loose even when its mounting bolt appears tight.
The problem was not simply the nominal handlebar diameter. The supplied bolt was too long for the available mounting depth on this particular motorcycle, causing it to reach the end of the threaded hole before the mirror base was fully secured.
Replacing it with an M6 × 20 mm bolt resolved the installation, and the rider confirmed the result on 5 July 2021.
The current Eclipse kit now includes both M6 × 20 mm and M6 × 25 mm mounting bolts, meaning that the shorter-bolt option used to solve this case is now included as part of the standard hardware package.
This case does not establish that every 2019 Street Scrambler requires the same bolt length. Production differences, VIN ranges, replacement parts, grips, bar-end accessories and previous-owner modifications may all affect the available mounting depth.
Current Street Scrambler fitment
At the time of writing, the KiWAV product page lists the Eclipse bar-end mirrors as compatible with:
- 2017-up Triumph Street Scrambler up to VIN 914447;
- original/OEM handlebars; and
- the model-specific Triumph water-cooled mounting option.
The product is not intended for aftermarket hollow handlebars under this fitment option.
See the current KiWAV Eclipse bar-end mirrors for Triumph water-cooled motorcycles for the latest package specifications and compatibility information.
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